L-PI-06-032, Response to Request for Additional Information Relief Request No. 2-RR-4-6
| ML061160281 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/25/2006 |
| From: | Thomas J. Palmisano Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-PI-06-032 | |
| Download: ML061160281 (2) | |
Text
Committed to Nuclear Excellence
/J' April 25, 2006 Prairie lsland Nuclear Generatinq Plant Operated by Nuclear Management Company, LLC L-PI-06-032 10 CFR 50.55a U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie lsland Nuclear Generating Plant Unit 2 Docket No. 50-306 License No. DPR-60 Response to Request for Additional Information Relief Request No. 2-WR-4-6 By letter dated September 8,2005, the Nuclear Management Company, LLC (NMC) submitted for review Relief Request No. 2-RR-4-6 for the Prairie lsland Unit 2 fourth 10-year Interval Inservice Inspection Program.
By phone call on April 5, 2006, the NRC Staff requested additional information on the original September 8, 2005 submittal. The enclosure to this letter states the NRC questions and the NMC responses.
Summaw of Commitments This letter contains no new commitments and no revisions to existing commitments.
7 3 ~ -
Thomas J. Palmisano Site Vice President, Prairie lsland Nuclear Generating Plant Nuclear Management Company, LLC Enclosure (1) cc:
Regional Administrator, USNRC, Region Ill Project Manager, Prairie lsland Nuclear Generating Plant, USNRC, NRR NRC Resident Inspector - Prairie lsland Nuclear Generating Plant Chief Boiler Inspector, State of Minnesota 171 7 Wakonade Drive East Welch, Minnesota 55089-9642 Telephone: 651.388.1 121
Enclosure I Response to Request for Additional Information Relief Request No. 2-RR-4-6 Clarification on Request for Relief No. 2-RR-4-6, for the Unit 2 fourth 10-year Interval lnservice Inspection Program NRC Question 1 :
In proposed Relief Request 2-RR-4-6, you did not indicate whether the limited scope volumetric examination of the 21 Residual Heat Removal (21 RHR) heat exchanger shell-to-flange weld provided any indication of the presence of unacceptable flaws or conditions in accordance with the acceptance criteria of Article IWC-3000 of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI.
Please discuss whether the limited scope volumetric examination of this weld provided any indication of the presence of flaws or other relevant conditions that were determined to be unacceptable according to the acceptance criteria of Article IWC-3000 of the ASME Code,Section XI.
NMC Response:
The limited scope volumetric examination of the subject weld did not provide any indication of the presence of flaws or other relevant conditions that were determined to be unacceptable according to the acceptance criteria of Article IWC-3000 of the ASME Code,Section XI. The recorded indications were identified as due to geometry and determined to be acceptable per Article IWC-3000 of the ASME Code,Section XI.
NRC Question 2:
Please discuss the extent to which the 21 RHR heat exchanger shell-to-flange weld was volumetrically examined during previous IS1 intervals, including the percentage of credible volumetric examination coverage that was achieved during the previous examinations.
NMC Response:
The 21 RHR heat exchanger shell-to-flange weld was volumetrically examined during the second 10 year IS1 interval as a limited exam, however coverage was not calculated. The recorded indications were identified as due to geometry. The subject weld was also inspected during the third 10-year ISI interval as a limited exam, with 32.5% coverage. The recorded indications were identified as due to geometry.